There isn't a gamestop store nearby you? And I think you can actually purchase things online directly from the bestbuy (or gamestop or others) website, don't have to go to the store. Also, even if the games aren't made anymore, according to BCVM, then you still probably can get them "used" in stores. Otherwise I guess Ebay would be a good choice for 4th gen games, just be sure to check the ratings of the seller beforehand to get a good idea whether the person is reliable or not, and that goes for all things you may buy there. Otherwise I don't know if there is an actual way to tell by the description whether the game is real or not. I hope you gave the person who gave you the fake gba game a very bad review/rating.
I have 2 Friend codes I use about equally. One is 4055-3723-1345 and the other is 0576 3520 6954. I'll try to mention which one to look for when needed, if I don't then ask.
I try to train pokemon with the best natures and IVs, but generally don't breed for IVs and occasionally use a pokemon that could have a better nature out of laziness (on the other hand I have reset or recaught the same species 20+ times to get the best nature and decent IVs sometimes). I somewhat do EV training, but don't calculate it out so it's perfect, just rely on the chart in the super training thing.